We have identified a number of tyrosine phosphoproteins in RSV-infected cells. These proteins were identified using anti-phosphotyrosine antibodies; many of them are also phosphorylated with [gamma-32P] ATP in situ in the cytoskeletal framework remaining after extraction of cells with Triton X-100. In collaboration with Professor P. M. Comoglio (University of Turin), we have begun to purify some of these proteins, with the intention of producing antibodies to them. We have already succeeded in the process of subcloning positive primary hybridoma cultures obtained from this mouse for the production of monoclonal antibodies. We wish to continue this collaborative effort.